Move libc_freeres_ptrs and libc_subfreeres to hidden/weak functions

They are both used by __libc_freeres to free all library malloc
allocated resources to help tooling like mtrace or valgrind with
memory leak tracking.

The current scheme uses assembly markers and linker script entries
to consolidate the free routine function pointers in the RELRO segment
and to be freed buffers in BSS.

This patch changes it to use specific free functions for
libc_freeres_ptrs buffers and call the function pointer array directly
with call_function_static_weak.

It allows the removal of both the internal macros and the linker
script sections.

Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>

7 files changed, 13 insertions, 8 deletions

diff --git a/misc/efgcvt-template.c b/misc/efgcvt-template.c
index 27a00a3ab5..00d0aa1d7e 100644
--- a/misc/efgcvt-template.c
+++ b/misc/efgcvt-template.c
@@ -22,6 +22,7 @@
 #include <sys/param.h>
 #include <libc-lock.h>
 #include <math_ldbl_opt.h>
+#include <set-freeres.h>
 
 #ifndef SPRINTF
 # define SPRINTF sprintf
@@ -38,7 +39,7 @@
 
 static char FCVT_BUFFER[MAXDIG];
 static char ECVT_BUFFER[MAXDIG];
-libc_freeres_ptr (static char *FCVT_BUFPTR);
+static char *FCVT_BUFPTR;
 
 char *
 __FCVT (FLOAT_TYPE value, int ndigit, int *decpt, int *sign)
@@ -73,3 +74,5 @@ __GCVT (FLOAT_TYPE value, int ndigit, char *buf)
   SPRINTF (buf, "%.*" FLOAT_FMT_FLAG "g", MIN (ndigit, NDIGIT_MAX), value);
   return buf;
 }
+
+weak_alias (FCVT_BUFPTR, __EFGCVT_FREEMEM_PTR);
diff --git a/misc/efgcvt.c b/misc/efgcvt.c
index 53673a08fe..f2a33afcdf 100644
--- a/misc/efgcvt.c
+++ b/misc/efgcvt.c
@@ -24,6 +24,7 @@
 #define __GCVT __gcvt
 #define __ECVT_R __ecvt_r
 #define __FCVT_R __fcvt_r
+#define __EFGCVT_FREEMEM_PTR __libc_efgcvt_freemem_ptr
 #include <efgcvt-dbl-macros.h>
 #include <efgcvt-template.c>
 
diff --git a/misc/fstab.c b/misc/fstab.c
index 0e04235a2b..ea4afc7d0f 100644
--- a/misc/fstab.c
+++ b/misc/fstab.c
@@ -177,7 +177,8 @@ fstab_convert (struct fstab_state *state)
 
 /* Make sure the memory is freed if the programs ends while in
    memory-debugging mode and something actually was allocated.  */
-libc_freeres_fn (fstab_free)
+void
+__libc_fstab_freemem (void)
 {
   char *buffer;
 
diff --git a/misc/hsearch.c b/misc/hsearch.c
index 615f7f08a3..f9a3f9267a 100644
--- a/misc/hsearch.c
+++ b/misc/hsearch.c
@@ -46,7 +46,3 @@ __hdestroy (void)
   __hdestroy_r (&htab);
 }
 weak_alias (__hdestroy, hdestroy)
-
-/* Make sure the table is freed if we want to free everything before
-   exiting.  */
-text_set_element (__libc_subfreeres, __hdestroy);
diff --git a/misc/mntent.c b/misc/mntent.c
index 4a1c5444cf..61dc63f253 100644
--- a/misc/mntent.c
+++ b/misc/mntent.c
@@ -19,6 +19,7 @@
 #include <mntent.h>
 #include <stdlib.h>
 #include <allocate_once.h>
+#include <set-freeres.h>
 
 struct mntent_buffer
 {
@@ -28,7 +29,7 @@ struct mntent_buffer
 
 /* We don't want to allocate the static buffer all the time since it
    is not always used (in fact, rather infrequently).  */
-libc_freeres_ptr (static void *mntent_buffer);
+static void *mntent_buffer;
 
 static void *
 allocate (void *closure)
@@ -56,3 +57,5 @@ getmntent (FILE *stream)
   return __getmntent_r (stream, &buffer->m,
 			buffer->buffer, sizeof (buffer->buffer));
 }
+
+weak_alias (mntent_buffer, __libc_mntent_freemem_ptr)
diff --git a/misc/qefgcvt.c b/misc/qefgcvt.c
index 91a3e2014a..a4ea8b801e 100644
--- a/misc/qefgcvt.c
+++ b/misc/qefgcvt.c
@@ -24,6 +24,7 @@
 #define __GCVT __qgcvt
 #define __ECVT_R __qecvt_r
 #define __FCVT_R __qfcvt_r
+#define __EFGCVT_FREEMEM_PTR __libc_qefgcvt_freemem_ptr
 #include <efgcvt-ldbl-macros.h>
 #include <efgcvt-template.c>
 
diff --git a/misc/unwind-link.c b/misc/unwind-link.c
index 63b655949e..c1e971b305 100644
--- a/misc/unwind-link.c
+++ b/misc/unwind-link.c
@@ -131,7 +131,7 @@ __libc_unwind_link_after_fork (void)
     }
 }
 
-void __libc_freeres_fn_section
+void
 __libc_unwind_link_freeres (void)
 {
   if (global_libgcc_handle != NULL)